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  2. Biological functions of hydrogen sulfide - Wikipedia

    en.wikipedia.org/wiki/Biological_functions_of...

    Animals and humans naturally produce some hydrogen sulfide in their body; researchers have proposed that the gas is used to regulate metabolic activity and body temperature, which would explain the above findings. [18] Two recent studies cast doubt that the effect can be achieved in larger mammals.

  3. Hydrogen sulfide - Wikipedia

    en.wikipedia.org/wiki/Hydrogen_sulfide

    100 ppm IDLH (NIOSH): immediately dangerous to life and health (the level that interferes with the ability to escape) 0.00047 ppm or 0.47 ppb is the odor threshold, the point at which 50% of a human panel can detect the presence of an odor without being able to identify it. [71] 10–20 ppm is the borderline concentration for eye irritation.

  4. Sulfur metabolism - Wikipedia

    en.wikipedia.org/wiki/Sulfur_metabolism

    Microbial sulfur cycle. Some bacteria use light energy to couple sulfur oxidation to carbon dioxide (CO 2) fixation for growth. These fall into two general groups: green sulfur bacteria (GSB) and purple sulfur bacteria (PSB). [6] However, some Cyanobacteria are also able to use hydrogen sulfide as an electron donor during anoxygenic ...

  5. Sulfur cycle - Wikipedia

    en.wikipedia.org/wiki/Sulfur_cycle

    The important sulfur cycle is a biogeochemical cycle in which the sulfur moves between rocks, waterways and living systems. It is important in geology as it affects many minerals and in life because sulfur is an essential element (), being a constituent of many proteins and cofactors, and sulfur compounds can be used as oxidants or reductants in microbial respiration. [1]

  6. Chemosynthesis - Wikipedia

    en.wikipedia.org/wiki/Chemosynthesis

    Venenivibrio stagnispumantis gains energy by oxidizing hydrogen gas.. In biochemistry, chemosynthesis is the biological conversion of one or more carbon-containing molecules (usually carbon dioxide or methane) and nutrients into organic matter using the oxidation of inorganic compounds (e.g., hydrogen gas, hydrogen sulfide) or ferrous ions as a source of energy, rather than sunlight, as in ...

  7. Hypothetical types of biochemistry - Wikipedia

    en.wikipedia.org/wiki/Hypothetical_types_of...

    Hydrogen sulfide life might use a mixture of carbon monoxide and carbon dioxide as their carbon source. They might produce and live on sulfur monoxide , which is analogous to oxygen (O 2 ). Hydrogen sulfide, like hydrogen cyanide and ammonia, suffers from the small temperature range where it is liquid, though that, like that of hydrogen cyanide ...

  8. Dissimilatory sulfate reduction - Wikipedia

    en.wikipedia.org/wiki/Dissimilatory_sulfate...

    The term "dissimilatory" is used when hydrogen sulfide (H 2 S) is produced in an anaerobic respiration process. By contrast, the term "assimilatory" would be used in relation to the biosynthesis of organosulfur compounds, even though hydrogen sulfide may be an intermediate. Dissimilatory sulfate reduction occurs in four steps: [1]

  9. Sulfur-reducing bacteria - Wikipedia

    en.wikipedia.org/wiki/Sulfur-reducing_bacteria

    Human activities such as burning fossil fuels, also contribute to the cycle by entering a significant amount of sulfur dioxide in the atmosphere. [66] The earliest life forms on Earth were sustained by sulfur metabolism, and the enormous diversity of present microorganisms is still supported by the sulfur cycle. [66]